Recently, electric optical devices have been developed such as liquid crystal devices, organic EL devices and electrophoresis devices. For example, as described in Japanese Unexamined Patent Publication No. 2001-291738, liquid crystal devices are generally structured with a liquid crystal panel, having a board on which a thin-film transistor is formed, being connected to a flexible printed circuit containing, for example, IC chips, which may drive the liquid crystal panel. In electric optical devices having this kind of liquid crystal device, generally the process of connecting a board and a flexible printed circuit includes removal of a protective organic film covering the terminal of the board by photolithography or etching. Generally, a flexible printed circuit is then positioned with an anisotropic conductive film or anisotropic conductive paste between the terminal of the board and the terminal of the flexible printed circuit being connected to the terminal of the board. The terminal of the board and the terminal of the flexible printed circuit can then be connected by heating the anisotropic conductive film or the anisotropic conductive paste while pressurizing the flexible printed circuit.